#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int n = nums.size();
        int left = 0, right = n - 1;
        while (left <= right)
        {
            int mid = left + (right - left) / 2;
            if (nums[mid] < target) left = mid + 1;
            else if (nums[mid] > target) right = mid - 1;
            else return mid;
        }
        return -1;
    }
};